So I'm looking to add on solar to my small vintage trailer (ground mount, not roof top), as well as charge the battery from the tow vehicle (does have 7-pin) while towing. I have to be space conscious, but I do think I have enough space to put in the parts I need which also has a vent above it, so any heat will have a chance to vent.
Primary loads would be a Dometic 12v compressor fridge (up to ~5+A depending on model I can fit), various lights, some BT battery speakers/phones/etc, and DC-DC boost for my laptop.
For the ground mount, I'm going to do collapsible frame angle aluminum bolted together, with flexible solar panels to safe some weight and physical space. Expandable, since sometimes I might need just a little, and other trips will be for longer and I'll need a lot more. I'm looking 2x100W and for the longer trips 4x100W.
I will also be wanting a 110v charger for when connected to shore power, although it's not as high a priority initially and I'm OK with a slightly awkward, annoying setup to start with.
Parts I'm looking at, to make it all work, is SmartSolar MPPT 150/35, BMV-712 Smart Monitor, Orion-Tr Smart DC-DC Charger Isolated 12-12 18a (connect to the 7-pin AUX), Blue Smart IP65 120v 15a.
I'll of course get appropriate MC4 pass-through, breakers/disconnects/fuses/bus bars, and mount behind some standoffs and acrylic to shield from accidents.
Unfortunately the Orion doesn't offer the VE.Direct, so only the SmartSolar and BMV will be connected. Can I put the BMV shunt right at the battery terminal (in terms of wiring) and be able to monitor input/output of the battery correctly, whether its from solar, the Orion, or the Blue Smart 120v chargers? I don't ever expect to have all 3 hooked up at once, given my setup.
For the Orion, it only provides power in 1 direction, correct? So if I turn off the car but leave it connected to the trailer, the Orion prevents back-feeding to the car power, right? And can I have it detect when the car is off (alternator isn't running), or do I need to wire some kind of switch or the like for the starter detect relay? Or is there some kind of alternator running detector I can find that'll do that automatically for me? I don't want the trailer to drain the vehicle battery when it's sitting there for an extended period of time.
Do those parts look correct/reasonable for a 100Ah LiFePO4? Anything else I should consider?